1. Field of the Invention
This invention relates to a battery device loaded on a moving body, such as a car or a vessel. As an example, the invention relates to a battery device that may be loaded with advantage on a hybrid system car where the battery and an internal combustion engine are selectively switched so as to be used alternatively as a driving source.
2. Description of Prior Art
For coping with the problems of resources and environment, an electric car, having a battery device as a driving source, is attracting attention as substitution for a gasoline engine car or a diesel engine car. Up to now, a lead accumulator has been used as a driving source for the car electric system. Thus, in the development of an electric car, the battery device used was basically a lead accumulator. However, in order to realize a practically satisfactory running distance by charging only once, an excessively large size or weight of the battery device poses a problem in connection with the use of the lead accumulator.
For this reason, attempts are being made for developing a practically usable hybrid car system where switching is suitably made between an electric motor and a conventional internal combustion engine depending on the running conditions to suppress the excessive size of the battery device fishing the power to the motor as well as to achieve energy saving and cleanness in operation. On the other hand, attempts are being made to use a lithium ion secondary battery in place of the conventional lead accumulator, in view of the high performance and lightness in weight of the lithium ion secondary battery, in consideration that a higher voltage of tens to hundreds of volt, a higher energy density and higher output specifications are demanded of the car battery device.
For example, in Japanese Laying-Open Patent H-9-86188 entitled xe2x80x9cBattery Device for Electric Carxe2x80x9d, there is disclosed a car battery device in which a large number of lithium ion secondary batteries are accommodated in a large number of separate chambers in a battery casing split into an upper half and a lower half, the abutting surfaces of which are formed as-one with a large number of semi-cylindrical ribs. The battery casing is completed on unifying the upper and lower halves together. At this time, a large number of separate chambers are formed by facing ribs for accommodating columnar-shaped lithium ion secondary batteries.
The ribs are formed with several grooves at several longitudinal points. In these grooves, an adhesive for cementing the lithium ion secondary batteries is charged into these grooves. On unifying the upper and lower halves together to complete the battery casing, the respective lithium ion secondary batteries are sandwiched between the neighboring ribs and are secured in position by the adhesive applied at several longitudinal points.
In the above-described prior-art car battery device, the respective lithium ion secondary batteries are protected against severe vibrations or shocks by being housed in the separate chambers defined by arcuate partitioning wall sections provided in the battery casing and by being secured by an adhesive applied at the several longitudinal points. Therefore, if, in the prior-art car battery device, an excessive amount of the adhesive is charged into a groove in the partitioning wall section, the lithium ion secondary battery accommodated therein is floated so that it is not cemented fixedly to the inner periphery of the partitioning wall section. In the prior-art car battery device, the lithium ion secondary batteries tend to be moved due to vibrations or the like, under the low bonding force caused by such floating, thus raising the problem of insufficient contact. Thus, in the above-described prior-art car battery device, charging of the adhesive needs to be performed under meticulously controlled conditions to apply the adhesive evenly in the large number of grooves, thus lowering the operating efficiency.
Moreover, in the prior-art car battery device, a large number of lithium ion secondary batteries are accommodated in the battery casing, and are cemented in position with an adhesive. Thus, in the prior-art car battery device, a large quantity of the adhesive is used and a large number of process steps are involved in charging the adhesive to the grooves, with the result that the production cost tends to be raised. Moreover, the prior-art car battery device suffers from the problem of increased overall weight due to the use of a large quantity of the adhesive.
In addition, in the prior-art car battery device, the lithium ion secondary batteries are accommodated in one of the battery casing halves, after which the other battery casing half is bonded to the firstly stated half to perform the processing of the next process step. Thus, the prior-art car battery device suffers from the problem that extremely labor-consuming operations of accommodating a large number of lithium ion secondary batteries and assembling the battery casing halves are required, while the adhesive needs to be cured over a prolonged time, thus lowering the efficiency.
On the other hand, in the prior-art car battery device, the lithium ion secondary batteries are manufactured by separate steps and accommodated in the battery casing. In the prior-art car battery device, operating tests are conducted following the above-described assembling operations. If malfunctions in certain lithium ion secondary batteries are found by this operational test, the entire car battery device has to be rejected because considerable difficulties are met in replacing the malfunctioning lithium ion secondary batteries cemented in position in the battery casing by the adhesive.
In the car battery device, a variety of detection sensors, such as a voltage sensor or a temperature sensor, are provided to assure normal and safe operations. The car battery device is constructed so that the lithium ion secondary batteries are checked for unusual heat evolution by e.g., a temperature sensor and, if such unusual heat evolution is detected, an unusual situation detection signal is sent from the temperature sensor to a controller to execute a pre-set control operation.
In the prior-art car battery device, a temperature sensor is cemented on the outer periphery of the pre-set lithium ion secondary batteries with an adhesive and the entire assembly is housed in this state in the battery casing. The prior-art car battery device thus suffers from the problem that there is required a process step of holding the temperature sensor by e.g., a holding jig on the outer periphery of the lithium ion secondary batteries, until the adhesive is cured, thus again lowering the efficiency. Also, the prior-art car battery device suffers from the problem that stable detection operations cannot be realized because no measures are used to control the mounting position of the temperature sensor on the lithium ion secondary battery.
It is therefore an object of the present invention to provide a battery device loaded on a moving body where a large number of secondary batteries can be efficiently accommodated and fixedly cemented in position in the battery housing section in a modular casing, malfunctioning batteries, if any, can be readily exchanged and unusual heat evolution can be detected in stability.
The present invention provides a battery device for loading on a moving body including a modular casing having a battery housing section therein and a large number of terminal openings, a large number of secondary batteries housed in the battery housing section so that terminal portions thereof are exposed to outside through the terminal openings, an adhesive charging opening and an adhesive efflux opening part in register with each terminal opening. The adhesive efflux opening part communicates with each terminal opening and with the adhesive charging opening, so that the adhesive efflux opening part causes the adhesive charged through the adhesive charging opening to flow around the peripheral surface of the secondary battery. The secondary battery is cemented to peripheral wall portions around the terminal openings.
In the battery device for loading on a moving body, according to the present invention, if, with the secondary battery housed in the battery housing section in the modular casing, the adhesive is charged through the adhesive charging opening, this adhesive is allowed to flow through the adhesive efflux opening part to the terminal opening to become attached to the peripheral surface of the secondary battery to secure the secondary battery to the terminal opening. In the battery device for loading on a moving body, if the amount of the adhesive charged into the adhesive charging opening exceeds a moderate amount, it is allowed to overflow the opening to indicate that a moderate amount of the adhesive has been charged to permit facilitated control of the adhesive charging volume.
Thus, in the battery device for loading on a moving body, the secondary battery can be fixedly bonded in the battery housing section of the modular casing with a small amount of the adhesive, whilst the cost of the material or the number of process steps or the overall weight can be decreased. On the other hand, in the battery device for loading on a moving body, since the secondary batteries are housed in a floated state in the battery housing section, the flow duct for the cooling air is secured in the inside of the device to permit efficient cooling.
In the battery device for loading on a moving body, there is formed a punching guide groove around the terminal opening. If, in the battery device for loading on a moving body, malfunctions of a secondary battery are found out in a post-assembly operating test, the outer periphery of the terminal opening is punched along the punching guide recessed groove to form a punched opening through which to take out the secondary battery housed in the battery housing section. In the battery device for loading on a moving body, only malfunctioning secondary batteries can be exchanged with manifest economic advantages.
In the battery device for loading on a moving body, the temperature detection sensor is assembled in the adhesive charging opening to secure a detection part of the temperature detection sensor through the adhesive efflux opening part to the vicinity of the outer periphery of the secondary battery. Therefore, in the battery device for loading on a moving body, the temperature detection sensor can be assembled easily to permit temperature control of the secondary batteries with stability and high accuracy.
In the battery device for loading on a moving body, a number of adhesive charging openings and adhesive efflux opening parts are formed in register with the terminal openings formed in the modular casing having the battery housing section defined therein. The adhesive charged from the adhesive charging opening flows out via the adhesive efflux opening part to the terminal openings to secure the ends of the secondary batteries to the terminal openings. In the battery device for loading on a moving body, not only is the amount of adhesive consumption reduced, but the adhesive is allowed to overflow the opening to indicate charging of a moderate amount of the adhesive to assure reliable bonding of the secondary batteries, with the result that the cost and/or the weight can be reduced to reduce the mounting defects of the secondary batteries to improve the quality of the battery device.
Moreover, in the battery device for loading on a moving body, according to the present invention, a punching guide recessed groove is formed around the terminal opening, such that, if a secondary battery is found to be malfunctioning in the post-assembly operation test, the outer periphery of the terminal opening can be punched along the punching guide recessed groove to form a punched opening through which the malfunctioning secondary battery can be easily taken out from the battery housing section and exchanged without the necessity of taking measures for disposal of the entire device.
In addition, in the battery device for loading on a moving body, according to the present invention, the temperature detection sensor is mounted in the adhesive charging opening so that its detection part can be maintained at a constant position relative to the secondary battery to simplify the mounting operation. This permits temperature control to high precision and a simplified mounting operation.